Psychology and mental health

The importance of ingestion rates for estimating food quality and energy intake

Article Abstract:

The ingestion rates are found to vary more among different food items than among different adult individuals. The variation in nutritional content and ingestion rates are analyzed among different plant parts and food categories. The analyses of two populations of Hanuman langurs have indicated that although different food characteristics are traded off against each other, in the general the highest-quality food in a primate's diet is not only rich in energy and relevant nutrients, but also easy to digest and ingest.

What Hanuman langur males know about female reproductive status

Article Abstract:

An investigation was carried out to assess what Hanuman langur males knew about female reproductive status, as indicated by changes in male behavior, such as rates of copulations, anogenital inspections, and consortships, in relation to different female receptive periods. Results showed that males were more interested in fertile than pregnant females, based on consortships males could distinguish fertile from nonfertile phases, as well as fertile, nonconceptional receptive periods from conceptional ones.

Genital swellings in silvered langurs: What do they indicate?

Article Abstract:

The occurrence of genital swellings in silvered langurs (Trachypithecus cristatus) is examined. The reasons for genital swellings have remained unclear, but the primates might exhibit three kinds of genital swellings, including exaggerated swellings that most closely indicate fertility and early pregnancy and much smaller swellings that indicate fertility or late gestation.